1. Field of the Invention
The present invention relates to a seatbelt system for restraining and protecting an occupant of a vehicle in an emergency, and more particularly to improvements in a fully passive type seatbelt system wherein means for driving the webbing is automatically actuated in accordance with the actions of the occupant in entering or leaving the vehicle so as to fasten the webbing to the occupant or release the webbing from the occupant.
2. Description of the Prior Art
To secure the safety of the occupant in a collision accident to the vehicle, there have heretofore been used seatbelt systems. To further improve the safety of the occupant, there have been proposed the so-called fullpassive type seatbelt systems capable of automatically fastening the webbing for restraining the occupant or releasing the webbing in accordance with the actions of the occupant in entering or leaving the vehicle.
In said full-passive type seatbelt system, the webbing for restraining the occupant is secured at one end thereof to the side surface of a seat for the occupant on the side opposite the door and at the other end thereof to the door. The portion of the webbing mounted on the door is moved by driving means such as a motor in the longitudinal direction of the vehicle, whereby a space formed between the webbing and the seat for the occupant is expanded or contracted, so that the space for the occupant to enter or leave the vehicle can be obtained when the occupant enters and leaves the vehicle, and the webbing can be reliably fastened to the occupant after the occupant has entered the vehicle. Additionally, a switch for detecting the conditions of the door being open or closed is provided in an electric circuit of said motor. In the case of the door being closed, the webbing is moved toward the rear of the vehicle, i.e. in the direction of the seat to have the occupant fastened thereto with the webbing, and, in the case of the door being open, the webbing is moved toward the front of the vehicle to form a space sufficient for the occupant to enter and leave the vehicle between the webbing and the seat for the occupant.
FIG. 1 shows one example of the full-passive type seatbelt system which have been proposed heretofore. In the drawing, designated at 10 is a vehicle body, 12 a seat for an occupant being disposed on the floor of said vehicle body 10, a webbing retractor 14 solidly secured to the side surface of said seat 12 on the side nearest the center of the vehicle, a guide rail 16 provided on the roof side member of the vehicle body 10, a slide plate 18 slidable along said guide rail 16 in the longitudinal direction of the vehicle, a webbing 20, the inner end 20a of which is wound up into said retractor 14 by its biasing force and the outer end 20b of which is engaged with said slide plate 18, a retractor 22 solidly secured to the roof side member of the vehicle for constantly biasing said slide plate 18 toward the rear of the vehicle through a narrow width webbing 24, and driving means 26 for moving said slide plate 18 in the longitudinal direction of the vehicle by winding up one end of a wire 28, the other end of which is fixed on said slide plate 18. Here, the driving means 26 is adapted to be operated on detecting the action of the occupant leaving the vehicle. For instance, if the occupant opens the door for entering or leaving the vehicle, said driving means is operated by an opened door detecting signal emitted then. Furthermore, said driving means 26 is adapted to deliver the wire 28 by an action of the occupant being seated, e.g. by closing the door after he is seated. With the abovedescribed full-passive type seatbelt system, in the case of the door being closed, the webbing is moved toward the rear of the vehicle, i.e. in the direction of the occupant's seat, whereby the webbing is fastened to the occupant, and, in the case of the door being open, the webbing is moved toward the front of the vehicle, whereby a space sufficient for the occupant to enter or leave the vehicle is formed between the webbing and the seat for the occupant.
In the conventional fully passive type seatbelt system the webbing for restraining the occupant is automatically fastened to the occupant and released therefrom in accordance with the actions of the occupant in entering or leaving the vehicle, thus securing high safety for the occupant. However, with those conventional fully passive seatbelt systems, there have been encountered certain disadvantages. The control circuit for actuating the webbing driving means is very complicated and, nevertheless, in case the occupant has entered the vehicle and has fastened thereto the webbing, and thereafter, he is released electrically or mechanically from the restraint of the webbing, he has neither effective alternative measure for safety nor warning means.